Expandable seals have a swage driven through them and exterior features that are designed to engage and penetrate the surrounding tubular. Some designs feature circumferential ribs that have mirror image orientations in opposed directions that enable the seal to resist forces in opposed directions. Some designs add rubber sealing material that initially covers the ribs and that extends through the ribs when the seal is expanded from within. The ribs have relatively blunt points that to some degree deflect as the expansion progresses. In some instances additional gripping is warranted beyond the engagement of the angled ribs into the surrounding tubular and in those cases hardened inserts are used to enhance grip. In such case the insert particles are positioned to get more grip and in a manner of working with the angled ribs so as not to interfere with the flexing or penetration of such ribs into the wall of the surrounding tubular. U.S. Pat. No. 7,784,797 is a good example of such a design.
Other designs simply used hardened particles on an outer surface of a tubular that is expanded to anchor such tubular to the surrounding tubular. The hardened particles may be initially recessed for running in. Some examples of expandable anchors or seals are: U.S. Pat. Nos. 7,367,404; 7,124,826; 6,564,870; 7,661,470; 7,124,829; 7,954,516; 7,017,669 and 7,779,924.
What is not found in these prior designs is any way to effectively limit the radial expansion of such seals. Limiting the radial expansion prevents overstressing the seal that can initiate cracks especially under loading that can result in loss of grip. Overexpansion can overly flex the slanted ribs getting them to crack or have pieces break off. Various designs are illustrated that locate ring shape travel stops that have blunt leading ends to control the penetration or flexing of the inclined ribs against the surrounding tubular. Such blunt travel stops can also be equipped with raised sharp particles to accomplish a double duty of enhancing anchor grip while limiting radial expansion to limit stressing of the expanding ring that functions as the anchor. These and other features will be more readily apparent to those skilled in the art from a review of the preferred embodiments and associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.